This invention relates to an indoor-outdoor emergency warning system and in particular, to an add-on system that is audible coupled to an existing detector to furnish an alarm at a remote location that will aid rescuers in locating the source of the emergency and/or the location of people who might be in need of help.
Many occupied buildings, such as homes, are now equipped with a number of smoke or fire detectors. Each detector services a given region within its particular sensing range and upon detecting a potentially dangerous situation, generates an audible output signal. Some detectors are further equipped with some type of lighting device that is activated upon the sensing of an emergency to illuminate the involved region to find an escape route to safety. Smoke detectors equipped with lighting devices are described in further detail in U.S. Pat. Nos. 4,148,023; 4,257,039; 4,258,291 and 4,287,509. These devices, however, all suffer from one serious drawback in that the equipment is contained entirely inside the building within the danger zone. As a consequence, the equipment itself is usually consumed by the fire, and thus ceases to function after what might be a relatively short period of time. Furthermore, because the warning equipment is entirely contained inside the building, it is of little use in alerting people outside the building who might aid in combating the fire and/or rescuing those in the house such as children or invalids who typically are in need of such aid. When help does arrive, the rescuer generally has no way of knowing which parts of the building are most heavily involved and even more importantly, finding which areas are normally occupied by children, invalids or the like.